Automatically controlled hydraulic press intensifier



Nov.

29y 1932. F. KURATH AUTOMATICALLY coNTRoLLED HYDRAULIC PRESS INTENSIFIERFiled Aug. 16,` 1929 Patented Nov.a 29g 1932 STATES PATENT QFFICE FRANZKURTE, @F CHICAGO, ILLINOIS, ASSIGNOR T0 ECONOMY FUSE AND MFG. C0,

GF CHICAG, ILLINOIS, A; COREORATION OF NEW YORK ATMATICALLY CONTROLLEDHYDRAULIC PRES-S INTENSEBIER Application led August 16, 1929, Serial No.386,252.

This invention relates to improvements in automatically controlledhydraulic press intensiliers, and more particularly to improvements inhydraulic presses whereby an automatic control is provided to initiallyaotuate the press at a low pressure and finally increase the pressuresuciently high to perform the desired. pressing operation.

Hydraulic presses such as used in moldingfoperations are commonlyoperated by being connected to a low pressure fluid supply line. 1t istherefore necessary to use some arrangement of pressure intensier whichmay comprise a slidable piston, the

'ends of which are ofdiderential diameters whereby .the low pressureacting upon the larger end will transmit a greatly increased pressure toiiuid acting upon the ram of the press. llt is not desirable immediatelyto apply the high pressure upon actuating the press, and thereforemanually controlled valves have heen'provided so that the low pressureinitially moves the press platen into engagement with the work,whereupon by a manual control the low pressure is admitted to thepressure intensifier, thus developinfr the high pressure on the ram. s

statedu former constructions required two manual operations..

Sii)

llt is the purpose of this invention to improve upon the eiciency ofapparatus of the type described, whereby the operator only needs toact-nate one main valve. whereupon by automatic operation the ram willbe moved into engagement with the work at amount; of high pressurepiping` resulting in a more compact apparatus with less liability ofleakage or damage by bursting of the pipes.

Further and additional objects and advantages of my improvements will bemore readily apparent from the .following (le-- scr1pt1on taken in'connection with the` attached drawing, in which a preferred embodimentis specifically shown..

In the drawing,

Figure 1 is a fragmentary sectional elevation through a portion ofahydraulie press illustrating the improved intensifier and theyautomatic control therefor the parts being shown in high pressureposition with the press platen 1n engagement with the work.

Figure 2 is a fragmentary sectional elevation similar to Figure 1, butillustrating the parts in low pressure position.

In describing my invention, it will be understood that the apparatus isadaptable to many forms and arrangements of presses, and the pipinglconnections may `be considerably modified without departing from thespirit of my invention. Since the press may be loit any conventionaltype, only a fragmentary showing' has been made. Thus/in the drawing, 10is a fixed lower press platen, while 11 is an upper vertically movablepress platen. 1t will be understood that the upper press platen isguided in any desired manner. and is preferably normally held by springsor other means in raised position. The piece of work shown in dottedlines is designated 12. AFigure 2 shows the upper platen 11 in raisedposition, while Figure 1 shows the platen in engagement with the work12.

A vertically slidable piston ram 13 is ram 13 and prevents leakage ofthe high fluid pressure. the packing being retained by the flanged ring16 .which is bolted into the lower end of the cylinder 14. The cylinder14 is closed at its upper end by a head 17, having an opening 18extending therethrough. The f upper portion of the opening is enlargedand screwthreaded as at 19 to provide a seat and means for attaching ahousing forming a. pressure intensifier 20. The intensifier 20 includesa cylinder 21 closed at the upper end -bv a head 22 vand at its lowerend by a cylindrical block 23. 'lfhecylindrical block 23 into theopening 18 and thus into the chamber i 28 above the ram 13. The block 23is formed with a tubular recess 29 which is oit a substantially smallerdiameter than the main part ot the chamber 30 within the cylinder 21.The two chambers ot diderent diameters 29 and 30 arey in communicationand i serve to .guide a slidable piston 31. @ne end of the piston 31extends to a head 32 and is et small diameter to be received in thechamber 29. 'lhe other end ot the piston designated 33 is of lar erdiameter and slides in the chamber 30. up-shaped leather packing 3d isattached to the lower face o the head 32 and similar cup-sha ed packing35 is attached to the u per ace ci the head 33.

A lluid supp y line Ll() extends from some suitable source ont lowpressure duid which may be preferably oil. Supply line Li0 has connectetherein, a T-connection d1 to which is attached the pipe 412. Adjacentthe ln-connection 'l1 is a checlr valve d3 which acts to allow the huidto dow from the right to the left as shown in the drawing, but willprevent any backward how of the duid. To the lett ot the check valve d3is a three-way valve tl operated by the handle t5. 'llo one side ot thethree-way valve is attached a return pipe 416 and upwardly extendingfrom the valve it is a pipe connection d?. A. short connecting pipe i8threaded into a wall ci the cylinder M communicates with an o ening t9which leads into the chamber 28 above the ram 13. Another connectingpipe upon operation of the apparatus, constitutes an extension of theipe l2 and is threaded into the head 22 ot t e intensifier cylinder 20,a suitable opening 51 being formed in the head 22. A return line 52 isconnected to the opening 53 at the lower end ot the chamber 36 andbeneath the enlarged piston head 33 ot the pressure intensifier. Thereturn line 52 connects to the main return line t6 at the 1F-coupling5t. lin line 52 is provided a iT-coin piling 55 to which is attached apipe connection -56 which is in communication with the pipe 50 when theapparatus is not in use.

lit will be understood that admission ot low pressurethrough the pipe t8will cause the ram 13 to torce the platen 11 into engagement with thework and at the same time will impart an u ward thrust to the piston 31.Admission o low 'pressure to the pipe 50 due to the diderence in areasof the heads of the piston 31 will result in a greatly increasedpressure being transmitted to the chamber 28 and thus cause the ram 13to impart the To the right ofthe head 6e neaaeeo desired pressure to thework. lt is desirable Athat the apparatus be automatic in its operation,whereby the operator will need onl to move a main control valve. Thus,accor ing to my invention, the operator places the work in position andthen moves the main valve tt, whereupon the platen 11 will be moved intoengagement with thework at a low pressure and by automatic operation thepressure will be brought up to a high working pressure. Upon completionot the pressing operation., the operator only needs to move the val-ve111, whereupon the parts return to their initial position.

The automatic control comprises a iioating piston generally designated60 which is enclosed in a suitable casing 61. rl`he casing 61 includes achamber 62 of large diameter and a chamber 63 of small diameter. rl`hepiston 60 is formed with a left hand head 61 which tightly tits thelarge diameter chamber 62. is a cylindrical portion 65 which closelylits the smaller chamber 63. rlhe right hand head 66 of the piston 60 isof the same diameter as the cylindrical portion 65 and closely tits thechamber 63. Between the cylindrical portions 65 and 66 is a reduced neck67. rl`he left hand end only of the piston 60 requires to be sealed, andit is provided with a cupshaped leather packing 68. The connection pipe47 is threaded into the wall of the casing 61 and communicates with theduct 69 which leads into the chamber 62 to the left et the head 6d. Asimilar duct 70 entends trom the chamber 62`to communicate with the pipe48 which is also attached to the casing` 61. 'lhe pipe connection 4t2 isthreaded into the right hand end of the casing 61 and communicates witha duct 71 extending to the extreme right hand end of the chamber 61 anda duct Z2 which extends to an intermediate portion of the chamber 63.rl.`he ipe connection 50 is attached to the upper side ot casing 61 atan intermediate point and communicates with the duct 73 which extendsinto the chamber 62 at a oint between the duct 7 2 and the left brandendof the chamber 62. The return connection 56 is also attached to thecasing 61 and communicatesl with the duct 74 at the point between thechambers 62 and 63. Cylindrical recesses '(5 are provided in theinterior et the casing 61 and connect with the litt" ice ducts in orderto permit tree dow. A control valve 7 6 may be provided in the pipe linet2 and is actuated by the handle 77. rlhis valve 'i' 6 may or may not benecessary or desirable. The o eration oi the apparatus will now bedescri ed.

The parts are shown in idle position in Figure 2, with the platen 11 inraised position. 'lhe valve handle 45 has been moved to an operativeposition, and will permit the oil pressure duid supply to dow from pipeline t0 through the check valve 43 through tra ' act through the pipesthe valve 44, through the-piple connection 47,

through the duct 69 to yt e chamber 62 through the duct into the pipe48' and from the pipe 48 directly into the chamber 28 behind theiston13. The low pressure will serve to orce the ram 13 downward againstthe resistance of the springs or other means which hold the platen 11 inraised position, and will force the platen into engagement with thework. At the same time,

the low pressure will act upward against the lower head 32 of theintensifier piston 31 and will force the iston 31 from its loweredposition shown in igure 2 to the raised position shown in Figure 1.During this movement oi the pistou 31 the pipe line 52 is open to returnwhile the pipe line 5@ on the upper end oi the intensifier chamber 3G isalso open to return by communication through the duct 7 3 to the reducedneck portion 67 of the automatic piston 60. rlihe reduced neck portion67 is also in communication with the duct 74 and thus through the pipe56 to the return pipe line 52. Theretore, there is no resistance toupward movement of the piston 31. At the same time the pipe line 42 willtransmit low pressure. to the right hand end of the chamber 63 whichwill be initially closed by the head 6.6 of the iston 60 which is in aposition moved to the et hand end. As soon as the platen 11 is inengagement with the work, the low pressure will build up in the chamber62 to the let oi the head 64 and will finally be sumcientl to move thepiston 6() to the right, since the head 64 is oi larger area than thehead 66. The movement of the piston 64 may be manually controlled by theoperation of the valve 76. Thus ii the valve 7 6 is in closed positionthe piston 60 will not be moved. When the pistou 60 is moved to theright, the parts will be in the position shown in Figure 1. The lowpressure duid supply will then How through the pipe 42 through the duct72 along the reduced neck portion 67 on the piston 60 through the duct73 and through the pipe line 50 into the upper end ot the intensifierchamber 30 and therefore lact upon the large diameter-head 33. A greatlyincreased pressure will therefore be developed by the small diameterhead 32 and be transmitted to the chamber 28 and tend to force thepiston 13 downward. The line 52 will still be open'tov return, but thepipe connection 56 will be vclosed by the movement of the cylindricalportion 65 of the piston 60 into the chamber 63. The high pressure willalso 48 and 47 but will be stopped by the check valve 43 from flowingbackward through the low pressure line.

It will therefore be apparent that the high pressure is `confined to theram chamber 28,

the lower portlon ofthe chamber 29 of the intensifier, the left hand endof the chamber 62 of the automatic valve and the pipe connections 47 and48. The packings 34 and 68 must therefore be suiliciently tight toprevent leakage. The high pressure will act and .cause the pressingoperation to be carried out. Upon completion, the operator moves thevalve 45 in order to open pipe line 47 to returnl through the pipe 46.The pressure will therefore be relieved from above the ram 13 and theram will be returned to its upward position by any means such assprings. The release of the pressure at the left hand of the piston 60will allow the piston 60 to be forced to the position shown in Figure 2,and the piston 31 will then be open to return on each side and willtherefore drop to the position shown in Figure 2. The parts will then bein position for another operation.

Various modifications and changes may be resorted to in adapting myinvention to conditions oi use, without departing from the spirit andscope of my invention as expressed in the appended claims.

I claim:

1.. Apparatus for carryingout pressing operations comprising apresscylinder, a low pressure iiuid supply, a fluid supply line leadingfrom said low pressure supply to said c linder, means in said vlinecontrolling the ow of fluid therethrough, a pressure intensifierassociated with said press cylinder and transmit high pressure to saidthe admission of low pressure to said intensifier, a luid supply lineleading from said low pressure supply to said intensiier, means forcontrolling the flow of iiuid through said last' mentioned line, saidlast named means being associated with the fluid supply line to saidcylinder to be automatically operated upon the admission of low pressureto said cylinder and additional manually adjustable means in the supplyline to said intensifier to control the rate of actuation of saidintensifier.

arranged to cylinder upon 2. Apparatus for carrying out pressing op-Aerations, comprising a press cylinder, a low pressure 'luid supply, a.iiuid supply line leading from said low pressure line to said p resscylinder, a manually operated valve in said supply line, apressureintensiier associated with said press cylinder and including adifferential piston arranged to receive low pressure at one end and totransmit high pressure from the other end to said press cylinder, afluid supply line leading from said lowy pressure supply to saidintensifier, an automatically shiftable plunger associated with both ofsaid supply lines and arranged to control the admission of low pressuretoA said intensifier, said plunger being operated upon the admission oflow pressure to said press cylinder and a manually operated valve in thesupply line between said shitable plunger and the low pressure supplyarranged to control the speed of movement ofI l said shiftable plunger.

3. ln a hydraulic press, a main pressure cylinder, a ram movabletherein, a low pressure fluid supply line leading to said main cylinder,a check valve in said fluid supply line preventing back flow at anytime, an auxiliary cylinder, a dill'erential piston slidable thereinhaving a large head at one end and a small head at the other end, afluid passage leading I reaches a predetermined amountand addiLL tionalmeans for controlling the rate ot automatic operation of said valvewhereby the movement of the di'erential piston produces a pressure insaid main cylinder and upon said ram greater than the pressure of thelow-- pressure fluid supply.

ll. ln a hydraulic press, a main pressure cylinder, a ram in saidcylinder, a pressure intensilier having its high pressure side incommunication With said main cylinder, a low pressure iiuid supply lineleading to said main cylinder, a branch duid conduit leading from saidsupply line to the low pressure side of said intensifier, a check valvein said supply line between the said branch conduit and said maincylinder preventing back dow of the `fluid at'any time, a differentialpiston valve normally held in position by the duid pressure in saidbranch conduit acting on the small end of said piston valve,`said pistonvalve in normal position closin said branch conduit to prevent actuationot said intensi lier and being exposed at its large end to the pressuredeveloped in said :main cylinder whereby the development of apredetermined pressure in said main cylinder causes automatic shiftingof said piston valve to permit actuation of said intensifier and amanually adustable valve in said branch conduit between said supply lineand said piston valve tor controlling the rate of shitting movement ofsaid valve.,

5. ln a hydraulic press, a main pressure cylinder, a ram in saidcylinder, a pressure intensifier having its high pressure side incommunication with said main cylinder, a low pressurel lluid supply lineleading to said main cylinder, a branch fluid conduit leading from saidsupply line to the low pressure side of said intensifier, a checlr valvein said sup ply line between the said branch conduit and said maincylinder preventing back tlow of the fluid at any time, amanually-operable two-way valve between said check valve and said maincylinder, a drain leading from said two-way valve, a did'erential areapiston valve exposed at its small end to the presassenso sure in saidbranch conduit and ex osed at its large end to the pressure in the uidsupply conduit between said two-way valve and said main cylinder, saidpiston valve being normally urged into position to close said branchconduit to prevent actuation ot said intensifier and adapted to beautomatically shifted to open said branch conduit upon the developmentof a predetermined pressure in said main cylinder, the shifting movementof said piston valve causing a back flow of uid in said branch. conduittowards said fluid supply line and a manually operable valve forcontrolling the basl; How ot' duid in said branch conduit to control therate of shitting movement oit said piston valvea l Signed at Chicago,illinois, this 'lth day ot August, i929.

v FRANZ KURATH.

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